The present invention relates to a key input means for information entry in a miniature electronic calculator or in a combination wristwatch and calculator.
In a conventional miniature electronic calculator, a key input means usually comprises push-button switches which develop key input signals upon manual depression. The push-button switch requires a considerably long stroke to ensure stable operation. This renders the miniature electronic calculator thick and, therefore, the push-button switches are not suited for fabricating a thin miniature electronic calculator and, especially, not suited for a combination wristwatch and calculator.
Moreover, a keyboard unit comprising a plurality of push-button switches requires a considerably large space to ensure accurate introduction of desired information. This precludes realization of a combination wristwatch and calculator of a compact size.